package gov.nist.applet.phone.media.protocol.transport;

import java.io.IOException;

import java.net.InetAddress;
import java.net.DatagramSocket;
import java.net.MulticastSocket;
import java.net.DatagramPacket;
import java.net.SocketException;

import javax.media.protocol.DataSource;
import javax.media.protocol.PushSourceStream;
import javax.media.protocol.ContentDescriptor;
import javax.media.protocol.SourceTransferHandler;
import javax.media.rtp.RTPConnector;
import javax.media.rtp.OutputDataStream;

public class RTPSocketAdapter implements RTPConnector
{

	DatagramSocket dataSock;
	DatagramSocket ctrlSock;

	InetAddress addr;
	int port;

	SockInputStream dataInStrm = null, ctrlInStrm = null;
	SockOutputStream dataOutStrm = null, ctrlOutStrm = null;

	public RTPSocketAdapter(InetAddress addr, int port) throws IOException
	{
		this(addr, port, 1);
	}

	public RTPSocketAdapter(InetAddress addr, int port, int ttl)
			throws IOException
	{

		try
		{

			if (addr.isMulticastAddress())
			{
				dataSock = new MulticastSocket(port);
				ctrlSock = new MulticastSocket(port + 1);
				((MulticastSocket) dataSock).joinGroup(addr);
				((MulticastSocket) dataSock).setTimeToLive(ttl);
				((MulticastSocket) ctrlSock).joinGroup(addr);
				((MulticastSocket) ctrlSock).setTimeToLive(ttl);
			}
			else
			{
				dataSock = new DatagramSocket(port, InetAddress.getLocalHost());
				ctrlSock = new DatagramSocket(port + 1,
						InetAddress.getLocalHost());
			}

		}
		catch (SocketException e)
		{
			throw new IOException(e.getMessage());
		}

		this.addr = addr;
		this.port = port;
	}

	/**
	 * Returns an input stream to receive the RTP data.
	 */
	public PushSourceStream getDataInputStream() throws IOException
	{
		if (dataInStrm == null)
		{
			dataInStrm = new SockInputStream(dataSock, addr, port);
			dataInStrm.start();
		}
		return dataInStrm;
	}

	/**
	 * Returns an output stream to send the RTP data.
	 */
	public OutputDataStream getDataOutputStream() throws IOException
	{
		if (dataOutStrm == null)
			dataOutStrm = new SockOutputStream(dataSock, addr, port);
		return dataOutStrm;
	}

	/**
	 * Returns an input stream to receive the RTCP data.
	 */
	public PushSourceStream getControlInputStream() throws IOException
	{
		if (ctrlInStrm == null)
		{
			ctrlInStrm = new SockInputStream(ctrlSock, addr, port + 1);
			ctrlInStrm.start();
		}
		return ctrlInStrm;
	}

	/**
	 * Returns an output stream to send the RTCP data.
	 */
	public OutputDataStream getControlOutputStream() throws IOException
	{
		if (ctrlOutStrm == null)
			ctrlOutStrm = new SockOutputStream(ctrlSock, addr, port + 1);
		return ctrlOutStrm;
	}

	/**
	 * Close all the RTP, RTCP streams.
	 */
	public void close()
	{
		if (dataInStrm != null)
			dataInStrm.kill();
		if (ctrlInStrm != null)
			ctrlInStrm.kill();
		dataSock.close();
		ctrlSock.close();
	}

	/**
	 * Set the receive buffer size of the RTP data channel. This is only a hint
	 * to the implementation. The actual implementation may not be able to do
	 * anything to this.
	 */
	public void setReceiveBufferSize(int size) throws IOException
	{
		dataSock.setReceiveBufferSize(size);
	}

	/**
	 * Get the receive buffer size set on the RTP data channel. Return -1 if the
	 * receive buffer size is not applicable for the implementation.
	 */
	public int getReceiveBufferSize()
	{
		try
		{
			return dataSock.getReceiveBufferSize();
		}
		catch (Exception e)
		{
			return -1;
		}
	}

	/**
	 * Set the send buffer size of the RTP data channel. This is only a hint to
	 * the implementation. The actual implementation may not be able to do
	 * anything to this.
	 */
	public void setSendBufferSize(int size) throws IOException
	{
		dataSock.setSendBufferSize(size);
	}

	/**
	 * Get the send buffer size set on the RTP data channel. Return -1 if the
	 * send buffer size is not applicable for the implementation.
	 */
	public int getSendBufferSize()
	{
		try
		{
			return dataSock.getSendBufferSize();
		}
		catch (Exception e)
		{
			return -1;
		}
	}

	/**
	 * Return the RTCP bandwidth fraction. This value is used to initialize the
	 * RTPManager. Check RTPManager for more detauls. Return -1 to use the
	 * default values.
	 */
	public double getRTCPBandwidthFraction()
	{
		return -1;
	}

	/**
	 * Return the RTCP sender bandwidth fraction. This value is used to
	 * initialize the RTPManager. Check RTPManager for more detauls. Return -1
	 * to use the default values.
	 */
	public double getRTCPSenderBandwidthFraction()
	{
		return -1;
	}

	/**
	 * An inner class to implement an OutputDataStream based on UDP sockets.
	 */
	class SockOutputStream implements OutputDataStream
	{

		DatagramSocket sock;
		InetAddress addr;
		int port;

		public SockOutputStream(DatagramSocket sock, InetAddress addr, int port)
		{
			this.sock = sock;
			this.addr = addr;
			this.port = port;
		}

		public int write(byte data[], int offset, int len)
		{
			try
			{
				sock.send(new DatagramPacket(data, offset, len, addr, port));
			}
			catch (Exception e)
			{
				return -1;
			}
			return len;
		}
	}

	/**
	 * An inner class to implement an PushSourceStream based on UDP sockets.
	 */
	class SockInputStream extends Thread implements PushSourceStream
	{

		DatagramSocket sock;
		InetAddress addr;
		int port;
		boolean done = false;
		boolean dataRead = false;

		SourceTransferHandler sth = null;

		public SockInputStream(DatagramSocket sock, InetAddress addr, int port)
		{
			this.sock = sock;
			this.addr = addr;
			this.port = port;
		}

		public int read(byte buffer[], int offset, int length)
		{
			DatagramPacket p = new DatagramPacket(buffer, offset, length, addr,
					port);
			try
			{
				sock.receive(p);
			}
			catch (IOException e)
			{
				return -1;
			}
			synchronized (this)
			{
				dataRead = true;
				notify();
			}
			return p.getLength();
		}

		public synchronized void start()
		{
			super.start();
			if (sth != null)
			{
				dataRead = true;
				notify();
			}
		}

		public synchronized void kill()
		{
			done = true;
			notify();
		}

		public int getMinimumTransferSize()
		{
			return 2 * 1024; // twice the MTU size, just to be safe.
		}

		public synchronized void setTransferHandler(SourceTransferHandler sth)
		{
			this.sth = sth;
			dataRead = true;
			notify();
		}

		// Not applicable.
		public ContentDescriptor getContentDescriptor()
		{
			return null;
		}

		// Not applicable.
		public long getContentLength()
		{
			return LENGTH_UNKNOWN;
		}

		// Not applicable.
		public boolean endOfStream()
		{
			return false;
		}

		// Not applicable.
		public Object[] getControls()
		{
			return new Object[0];
		}

		// Not applicable.
		public Object getControl(String type)
		{
			return null;
		}

		/**
		 * Loop and notify the transfer handler of new data.
		 */
		public void run()
		{
			while (!done)
			{

				synchronized (this)
				{
					while (!dataRead && !done)
					{
						try
						{
							wait();
						}
						catch (InterruptedException e)
						{
						}
					}
					dataRead = false;
				}

				if (sth != null && !done)
				{
					sth.transferData(this);
				}
			}
		}
	}
}
